Mechanism and function of Kv channel targeting

Kv通道靶向的机制和功能

• 批准号: 8423350
• 负责人: CHEN GU
• 金额: $ 27.93万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-03-01 至 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8423350
• 关键词: Action Potentials; Adaptor Signaling Protein; Adult; Adverse effects; Affect; Alternative Splicing; Ankyrins; Arrhythmia; Ataxia; Auditory; Axon; Binding; Biological Assay; Brain; Brain Diseases; Cells; Characteristics; Cognition; Complex; Computer Simulation; Data; Dendrites; Disease; Distal; Drug Targeting; Electrophysiology (science); Epilepsy; Family; Fluorescence Recovery After Photobleaching; Fluorescence Resonance Energy Transfer; Frequencies; Functional disorder; Gene Mutation; Genes; Goals; Health; Hearing; Hippocampus (Brain); Human; Image; Imaging Techniques; Interneurons; Intervention; Kinetics; Knockout Mice; Life; Mediating; Membrane; Mitogen-Activated Protein Kinases; Modeling; Molecular; Molecular Biology; Motor Activity; Motor Neurons; Multiple Sclerosis; Mutagenesis; Mutation; Myocardium; Nerve Degeneration; Neuronal Plasticity; Neurons; Output; Pattern; Peptides; Pharmacologic Substance; Phosphorylation; Phosphorylation Site; Phosphotransferases; Physiological; Play; Potassium; Property; Protein Binding; Protein Biochemistry; RNA Splicing; Regulation; Research; Role; Signal Pathway; Signal Transduction; Site; Sleep Disorders; Small Interfering RNA; Specificity; Synaptic Transmission; Techniques; Testing; Variant; Vision; base; cell type; cellular imaging; design; innovation; insight; interdisciplinary approach; kinase inhibitor; member; motor disorder; nervous system disorder; neuronal cell body; neuronal excitability; novel; novel strategies; novel therapeutics; painful neuropathy; patch clamp; voltage; Action Potentials; Adaptor Signaling Protein; Adult; Adverse effects; Affect; Alternative Splicing; Ankyrins; Arrhythmia; Ataxia; Auditory; Axon; Binding; Biological Assay; Brain; Brain Diseases; Cells; Characteristics; Cognition; Complex; Computer Simulation; Data; Dendrites; Disease; Distal; Drug Targeting; Electrophysiology (science); Epilepsy; Family; Fluorescence Recovery After Photobleaching; Fluorescence Resonance Energy Transfer; Frequencies; Functional disorder; Gene Mutation; Genes; Goals; Health; Hearing; Hippocampus (Brain); Human; Image; Imaging Techniques; Interneurons; Intervention; Kinetics; Knockout Mice; Life; Mediating; Membrane; Mitogen-Activated Protein Kinases; Modeling; Molecular; Molecular Biology; Motor Activity; Motor Neurons; Multiple Sclerosis; Mutagenesis; Mutation; Myocardium; Nerve Degeneration; Neuronal Plasticity; Neurons; Output; Pattern; Peptides; Pharmacologic Substance; Phosphorylation; Phosphorylation Site; Phosphotransferases; Physiological; Play; Potassium; Property; Protein Binding; Protein Biochemistry; RNA Splicing; Regulation; Research; Role; Signal Pathway; Signal Transduction; Site; Sleep Disorders; Small Interfering RNA; Specificity; Synaptic Transmission; Techniques; Testing; Variant; Vision; base; cell type; cellular imaging; design; innovation; insight; interdisciplinary approach; kinase inhibitor; member; motor disorder; nervous system disorder; neuronal cell body; neuronal excitability; novel; novel strategies; novel therapeutics; painful neuropathy; patch clamp; voltage

DESCRIPTION (provided by applicant): The long-term objectives are to understand how voltage-gated potassium (Kv) channels are localized into the proper subcellular compartments and how their localization affects neuronal excitability, and thus to develop new strategies for treating neurological diseases. Kv channel dysfunction causes diseases of brain, heart and muscle. Kv channels are the primary targets of pharmaceutical interventions to treat epilepsies, arrhythmias, neuropathic pain, and multiple sclerosis. Due to broad channel expression in many cell types, blockers or activators often bring severe side effects. Recent studies show that each Kv channel displays a distinct pattern of polarized targeting in neurons. It is the emerging theme that such polarized targeting affects neuronal excitability. However, the exact mechanism and function of Kv channel targeting remain mystery. Kv3 (Shaw) channels are unique among Kv channels in their high activation threshold and rapid deactivation kinetics. They are required for rapid spiking and involved in dendritic integration and transmitter release. Human adult-onset ataxia caused by mutations in Kv3.3 gene is a testament for their important functions. Reflecting their diverse functions, Kv3 channels display complex targeting patterns that are governed by unknown mechanisms. Our preliminary studies show that the two splice variants of Kv3.1 have identical channel properties but differentially regulate action potential firing. Interestingly, they differ in axon-dendrite targeting. Based on our preliminary data, we propose a new model that action potential firing is regulated by Kv3 channel targeting, which is in turn regulated by alternative splicing and protein phosphorylation. We will test three hypotheses in this model with three aims. By taking a multidisciplinary approach that includes electrophysiology, imaging, molecular biology and protein biochemistry techniques, we will determine whether: (Aim 1) polarized targeting of Kv channels is critical for action potential firing; (Aim 2) ankyrin G at the axon initial segment functions as a conditional barrier for Kv3 splice variants; (Aim 3) protein phosphorylation regulates Kv3 channel targeting and hence action potential firing. Our research will contribute to generate a new therapeutic strategy and reveal new drug targets for specifically controlling Kv3 channel functions in neurons, e.g. developing small peptides and kinase inhibitors as the treatment of ataxia, epilepsy and sleeping disorders.

描述（由申请人提供）：长期目标是了解电压门控钾（KV）通道如何将其定位于适当的亚细胞室中，以及它们的定位如何影响神经元的兴奋性，从而制定治疗神经疾病的新策略。 KV通道功能障碍会导致大脑，心脏和肌肉疾病。 KV通道是治疗癫痫，心律不齐，神经性疼痛和多发性硬化症的药物干预措施的主要靶标。由于许多细胞类型的通道表达广泛，因此阻滞剂或激活剂通常会带来严重的副作用。最近的研究表明，每个KV通道都显示出神经元中极化靶向的独特模式。这种两极分化的靶向影响神经元兴奋性是新兴主题。但是，KV通道靶向的确切机制和功能仍然是神秘的。 KV3（Shaw）通道在其高激活阈值和快速失活动力学中是独特的。它们是快速峰值所必需的，并参与了树突状集成和发射器释放。由Kv3.3基因突变引起的人类成年性共济失调是其重要功能的证明。反映其各种功能的KV3通道显示由未知机制控制的复杂靶向模式。我们的初步研究表明，KV3.1的两个剪接变体具有相同的通道特性，但差异地调节了动作电位触发。有趣的是，它们在轴突树突靶向方面有所不同。基于我们的初步数据，我们提出了一个新模型，即动作电势射击受KV3通道靶向的调节，而KV3通道的靶向又受替代剪接和蛋白质磷酸化的调节。我们将以三个目标检验该模型中的三个假设。通过采用包括电生理学，成像，分子生物学和蛋白质生物化学技术在内的多学科方法，我们将确定是否确定：（ AIM 1）KV通道的极化靶向对动作潜在的射击至关重要； （AIM 2）Ankyrin g处的轴突初始段充当KV3剪接变体的条件屏障； （AIM 3）蛋白质磷酸化调节KV3通道的靶向，从而调节动作的潜在触发。我们的研究将有助于产生一种新的治疗策略，并揭示新的药物靶标，以专门控制神经元中的KV3通道功能，例如发展小肽和激酶抑制剂作为共济失调，癫痫和睡眠障碍的治疗。